Do I get real compiler errors?

Yes. Code compiles against a real Rust toolchain, so borrow-checker and type errors appear exactly as they would locally.

Can I use external crates?

No. The playground runs single-file programs against the standard library only.

Is the Rust playground free?

Yes, free with no account required.

main.rs

Input

Output

Become A Rust Backend Engineer

All-in-one Rust course for learning backend engineering with Rust. This comprehensive course is designed for developers seeking proficiency in Rust.

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Online Rust Playground

Runs on Rust 1.40.0 · Free · No signup required

A free online Rust playground for backend engineers. Write Rust, compile it, and read the compiler's response immediately — no rustup install, no cargo project, no signup. Rust's compiler is the main thing you are negotiating with while learning it, so fast feedback matters more here than in most languages. Use the playground to test whether a borrow is valid, see exactly what the borrow checker objects to, check how a trait implementation resolves, or confirm what a match arm actually returns. Compilation happens server-side against a real Rust toolchain, so the errors and warnings you see are the genuine article, formatted the way cargo would format them. Standard input is supported. If you are learning Rust for backend services specifically, the playground connects to our Rust framework guides and projects.

Rust Playground — Frequently Asked Questions

Do I get real compiler errors?: Yes. Code compiles against a real Rust toolchain, so borrow-checker and type errors appear exactly as they would locally.
Can I use external crates?: No. The playground runs single-file programs against the standard library only.
Is the Rust playground free?: Yes, free with no account required.

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Ready to build real backends rather than test snippets? Explore backend engineering courses and projects at MasteringBackend.